1. Field of the Invention
The present invention relates to a transmitting apparatus, a receiving apparatus, and a transmitting/receiving system for digital data, such as a digital audio signal.
2. Description of the Related Art
Recently, a large number of digital appliances, such as digital wireless microphones, digital audio mixers, and digital camcorders are used to produce audio-visual productions. In such digital appliances, digital processing is carried out to record and edit audio and images.
In addition to real-time processing in the same way as analog processing carried out inside an existing analog appliance, such digital processing includes processing that incurs a delay, such as digital filtering and digital compression.
For example, when, during ENG (Electronic News Gathering) or studio recording, a plurality of audio signals(in the case of music, vocal, guitar, and bass tracks for example) are inputted into a digital audio mixer or a digital camcorder using individual digital wireless microphones, the delay before input into the digital audio mixer or digital camcorder will differ between the audio signals, due to differences in the internal circuit specifications and/or firmware of the digital wireless microphones that transfer the audio signals.
Accordingly, before the different audio signals (or alternatively the different audio signals and images picked up by a digital camcorder) are merged into a single production, it may be necessary to adjust the delays of the different audio signals inputted into the digital audio mixer or digital camcorder.
However, since the delay times of individual digital wireless microphones are not known in an existing system, the recording engineer or editor has had to measure the delays of the different audio signals and appropriately adjust the respective delays of the audio signals. This means that adjusting the delays takes a lot of time and effort.
Japanese Unexamined Patent Application Publication No. 2004-312281 discloses a technology for transmitting digital image data that is appended with attribute information (such as image pickup time/date and scene number) and information on image pickup conditions (such as the camera in use and shutter speed) as metadata and displaying the received metadata superimposed on images. However, a technology that can transmit and receive information that is useful in adjusting the delays of digital data is yet to be disclosed.